Items to get:
Crystals Items in SAO that have different effects. There are three types of known Crystals.

■Teleportation Crystals: These Crystals can be used to teleport to any town on any open level.
■Warp (aka Corridor) Crystals: These Crystals can be used to teleport to any area (even specific areas in any town or any mapped dungeon area) in an open level.
■Healing Crystals: A high-level healing item with instantaneous effects as opposed to healing potions that have an effect over time.
■Anti-Crystal (aka Crystal Nullification) Area An area where any kind of crystal is rendered ineffective (Teleportation, Warp or Healing)